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为了降低等离子堆焊过程中SiCp的烧损及改善SiCp的湿润性,采用改进的等离子喷焊枪在H13钢表面制备钴基镍包SiCp陶瓷增强复合堆焊层。用XRD对覆层的物相进行了鉴定;用OM和SEM分析了堆焊层组织;用显微硬度计测试了堆焊层的显微硬度。结果表明,堆焊层组织由结合区的胞状晶组织及涂层区的树枝晶以及一些颗粒相组成;堆焊层主要由Cr、Co等元素的硅化物和Cr的碳化物(Cr23C6、Cr7C3)及Co的固溶体组成,并在堆焊层顶层发现有少量的SiCp;显微硬度从表面向基体逐渐降低,呈梯度分布,堆焊层表面平均硬度(HV)可达800。
In order to reduce the burning of SiCp during plasma surfacing and improve the wettability of SiCp, an improved plasma spray gun was used to prepare a cobalt-based nickel-clad SiCp ceramic composite surfacing layer on the surface of H13 steel. The phase of the overlay was identified by XRD. The surfacing layer structure was analyzed by OM and SEM. The microhardness of the surfacing layer was tested by microhardness tester. The results show that the surfacing layer consists of the dendrites and some granular phases in the cell-like crystal structure and the coating zone of the bonded zone. The surfacing layer is mainly composed of silicides such as Cr and Co and carbides of Cr (Cr23C6 and Cr7C3) And Co solid solution, and a small amount of SiCp was found on the top layer of the overlay. The microhardness gradually decreased from the surface to the matrix and distributed in a gradient manner. The average surface hardness (HV) of the surfacing layer could reach 800.